Hole Data Blocks
are used for Center Drilling, Drilling, Tapping, Reaming and Boreing Holes. A hole Data Blocks must have a
minimum of 2 sections... a How and Where

"How" is what you are doing to the hole Examples of How
Operations are Drill Operations, Tap Operations, Bore/Ream Operations and Back Spotface.

"Where" is where the holes are going... Locations or Bolt Circle

You can have 2
or 3 Hole operations and then the Locations/Bolt Circle
and it will preform all the operations to those locations... This means you can center, drill and tap a set of holes with
just 1 Data Block. Here is an example of a Bolt Circle: